The 4.50 cm long second hand on a watch rotates smoothly.

1. what is its angular speed?
2. what is the speed of the tip of the hand?

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

A70 kg person standing in an elevator is accelerated upwards at a rate of 2.5 m/s2. what is the force of the elevator on the person? 770 n 250 n 875 n -525 n